#include <SFML/Graphics.hpp>
#include <time.h>
#include <iostream>
using namespace sf;

const int M = 20;
const int N = 10;

int field[M][N] = {0};

struct Point
{int x,y;} a[4], b[4];

int figures[7][4] =
{
    1,3,5,7, // I
    2,4,5,7, // Z
    3,5,4,6, // S
    3,5,4,7, // T
    2,3,5,7, // L
    3,5,7,6, // J
    2,3,4,5, // O
};

bool check()
{
   for (int i=0;i<4;i++)
      if (a[i].x<0 || a[i].x>=N || a[i].y>=M) return 0;
      else if (field[a[i].y][a[i].x]) return 0;

   return 1;
};


int main()
{
    srand(time(0));     

    RenderWindow window(VideoMode({320, 480}), "tetris");

    Texture t1,t2,t3;
    if (!t1.loadFromFile("/Users/zhangshuhan/Desktop/images/tiles.png")) {
        std::cerr << "Failed to load texture: tiles.png" << std::endl;
        return 1;
    }
    if (!t2.loadFromFile("/Users/zhangshuhan/Desktop/images/back.png")) {
        std::cerr << "Failed to load texture: back.png" << std::endl;
        return 1;
    }
    if (!t3.loadFromFile("/Users/zhangshuhan/Desktop/images/frame.png")) {
        std::cerr << "Failed to load texture: frame.png" << std::endl;
        return 1;
    }

    
    Sprite s(t1), background(t2), frame(t3);

    int dx=0; //水平移动距离
    bool rotate=0; //是否旋转
    int colorNum=1;//颜色编号
    float timer=0,delay=0.3; //记录时间；下落的延迟时间

    Clock clock;//计时

    while (window.isOpen())
    {
        float time = clock.getElapsedTime().asSeconds();
        clock.restart();
        timer+=time;

        while (const std::optional event = window.pollEvent())
        {
            if (event->is<sf::Event::Closed>())
                window.close();

            if (event->getIf<sf::Event::KeyPressed>())//
              if (sf::Keyboard::isKeyPressed(sf::Keyboard::Key::Up)) rotate=true;
              else if (sf::Keyboard::isKeyPressed(sf::Keyboard::Key::Left)) {dx=-1;}
              else if (sf::Keyboard::isKeyPressed(sf::Keyboard::Key::Right)) {dx=1;}
        }

    if (Keyboard::isKeyPressed(sf::Keyboard::Scan::Down)) delay=0.05;

    //// <- Move -> ///
    for (int i=0;i<4;i++)  { b[i]=a[i]; a[i].x+=dx; }
    if (!check()) for (int i=0;i<4;i++) a[i]=b[i];

    //////Rotate//////
    if (rotate)
      {
        Point p = a[1]; //center of rotation
        for (int i=0;i<4;i++)
          {
            int x = a[i].y-p.y;
            int y = a[i].x-p.x;
            a[i].x = p.x - x;
            a[i].y = p.y + y;
           }
           if (!check()) for (int i=0;i<4;i++) a[i]=b[i];
      }

    ///////Tick//////
    if (timer>delay)
      {
        for (int i=0;i<4;i++) { b[i]=a[i]; a[i].y+=1; }

        if (!check())
        {
         for (int i=0;i<4;i++) field[b[i].y][b[i].x]=colorNum;

         colorNum=1+rand()%7;
         int n=rand()%7;
         for (int i=0;i<4;i++)
           {
            a[i].x = figures[n][i] % 2;
            a[i].y = figures[n][i] / 2;
           }
        }

         timer=0;
      }

    ///////check lines//////////
    int k=M-1;
    for (int i=M-1;i>0;i--)
    {
        int count=0;
        for (int j=0;j<N;j++)
        {
            if (field[i][j]) count++;
            field[k][j]=field[i][j];
        }
        if (count<N) k--;
    }

    dx=0; rotate=0; delay=0.3;

    /////////draw//////////
    window.clear(Color::White);    
    window.draw(background);
          
    for (int i=0;i<M;i++)
     for (int j=0;j<N;j++)
       {
         if (field[i][j]==0) continue;
         s.setTextureRect(IntRect({field[i][j]*18,0},{18,18}));
         s.setPosition({static_cast<float>(j*18),static_cast<float>(i*18)});
         s.move({28,31}); //offset
         window.draw(s);
       }

    for (int i=0;i<4;i++)
      {
        s.setTextureRect(IntRect({colorNum*18,0},{18,18}));
        s.setPosition({static_cast<float>(a[i].x*18),static_cast<float>(a[i].y*18)});
        s.move({28,31}); //offset
        window.draw(s);
      }

    window.draw(frame);
    window.display();
    }

    return 0;
}
